fix release checksums filenames

server: log the listening URL (francoismichel#34)

release building: put musl in a separate directory to avoid conflicts…

… with libc

use musl when compiling for ARM

release script: generate a zip archive for windows

fix the release build file

client: better format agent-based identities

add checksums name templates to release builds

disable arm64 release build for ssh3-server on Linux

specify go version in build-release.yml